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(No Model.)

C. W. MARTIN.

SWING BRIDGE.

No. 380,906. Patented Apr. l0, 1888.

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NrrED STATES PATENT OEErCE.,

CHARLES WV. MARTIN, OF VALLAOEBURG, ONTARIO, CANADA.

SWING-BRIDGE.

SPECIFICATION forming part of Letters Patent No. 380,906, dated April 10, 1888.

Application filed June 2?, 1887. Serial No. 242,196. (No model.)

To @ZZ whom 'it may concern.-

Be it known that I, CHARLES W. MARTIN, of Wallaceburg, in the county of Kent and Province ofi Ontario, Canada, have invented new and useful Improvements in Swing- Bridges; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, which form a part of this speciiication.

This invention relates to new and useful improvements in automatic draw-bridge gates; and the invention consists in the peculiar means employed for automatically opening and closing a gate in the approaches of a drawbridge by the movement of the draw itself, all as more fully hereinafter set forth.

Figure 1 is a vertical longitudinal section showing the inner pier of the approach and the connecting end of a draw-bridge, and with my improved device applied thereto. Fig. 2 is an elevation of the pier shown in Fig. 1, looking toward the land side of the bridge. Fig. 3 is a horizontal section through the pier on the line x as, Fig. 1. Fig. 4 is an elevation of one end of the bridge, and Figs. 5 and 6 are details specifically referred to hereinafter.

In the accompanying drawings, which form a part of this speciiication, A is the inner end of one of the approaches of a draw-bridge, B the abutting end of the draw, and C the outer pier of the st-ationary part of the bridge, all of the usual construction.

In the center of the pier O, and on the side toward the draw, I pivotally secure, in any suitable manner, the lever D, the upper end of which carries a small anti-friction roller,a,and reaches within proximity to the under side of the draw-bridge, while to the lower end is secured one end of the chain or rope E.

Fand G are two sheavessecuredopposite each other to a common head, H, as shown in elevation in Fig. 5,which has projecting from its rear side a tubular stem, I, which extends through the pier, a suitable opening having been made through the pier to receive it. This tubular stem I is supported in position by suitable bearings, J J, which permit it to have alimited rotary motion therein. At the rear opening of said tubular stem is secured a sheave, K, which guides the chain E, after passing in a horizontal direction through the stem I, in a vertical direction upward, where the-end of said chain is connected with another chain, L, running over two sheaves, M M, which has its ends connected to the lower bar of a verticallysliding gate, N, as shown in Fig. 1.

The sliding gate Nis adapted to move up and down through an opening in the bridge, and has its ends projecting into suitable vertical guides, O O, which are preferably in the form of a box. Near the top of each box is secured a sheave, P, over which passes a suitable lrope or chain, Q, one end of which is secured near the outer end of the gate, while its other end carries a weight, R.

To the center of the end of the draw is secured a cam. S, as shown in Fig. 4, in such position as to interfere with the upper end ofthe lever D.

In practice, the parts being constructed and arranged substantially as described, the operation is intended to be as follows: When the draw is open, the lever D stands in the position shown in Fig. 2, which permits the gate N to close the pathway across the bridge, being held up in such positionv by the counterweights R. If the draw is in the act of clos ing, the cam S strikes the upper end of the lever D and detlects it to one side or the other, according to the direction in which the bridge swings. This movement draws the chain E over one of the sheaves F or G and through the tubular stem I, and by means of the connecting-chain L the gate is forcibly drawn down below the pathway of the bridge, preferably with its upper bar level with the floor of the bridge, and is retained in such position as long as the draw is closed. As soon as the draw is opened, the weights R are free to act and the lever-D is gradually drawn into position shown in Fig. 2, which permits the closing of the gate.

In case there should not be' suflicient room underneath the floor of the bridge for the Withdrawal of the gate, I construct the same as shown in Fig. 6, wherein the upper and lower bars are merely connected by chains, which per Vmits the gate to fold into a small compass.

It will be seen that my device permits the opening of the draw to either side :and provides absolute safety in case the bridge in closing is turned through its closed position by negligence of the operator; and, further, my

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device is extremely simple and not liable to get out of order.

The object of securing the sheaves F and G to the head H and providing the latter with a gate, of the oscillating,` lever D, chain E and 45y tubular stem, I, is to allow the sheaves to turn its operative connection With the gate, sheaves into the line of draft as the end of the lever D F and G, head H, stern I, secured in bearings, swings in a circular path. and the cam S, all arranged to operate sub- Vhat I claim as my invention is stan tially as described.

said stem, and connected with the gate, suhstantially as and for the purpose specified.

2. The combination, With a movablebridge- 15 l. The combination, with the movable CHARLES WV. MARTIN. ro bridgegate and the stem I, of the vertical os Witnesses:

cillating lever and the chain connected With H. S. SPRAGUE, the lower end of said lever, passed through I?. M. HULBERT. 

